Safety appliance for elevators.



No. 655,837. Patented Aug. |4,|900. A. A. E. STERZING.

SAFETY APPLIANcE Fon ELU/Mons.

(Application filed May 18, 1899.)

(No Model.)

2 Sheets-Sheet No. 655,837. Patented Aug. I4, |900. A. A. E. STERZING. v l

SAFETY APPLIANCE FDH ELEVATDRS.

(Application filed` May 13, 1899.) (No Model.) 2 Sheets-Sheet 2,

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- bear upon opposite side faces rire Sterns A'TENT einen ALBERT AUGUST ERNEST STERZING, OF NEW YORK, N. Y.

SAFETY APPLIANCE FOR ELEVATORS.

SPECIFICATION forming part of Letters :Patent N0. 655,837, dated. August 14, 190'0.

Application filed May `1 3, l B 9 9.

To LZZ whom t may concern;

Be it known that I, ALBERT AUGUST ERNEsT STERZING, a subject of the Queen of Great Britain, and a resident of New York city, in the countyof New York and State of New York, have invented certain new and useful Improvements in Safety Appliances for Elevators, of which the following is a specification.

My invention relates to a safety appliance for elevators, and has for its objects, first, to insure positively against the accidental fall of the elevator-car; second, to control and maintain the speed of travel of the car within certaindeiinite and safe limits, and,finally, to provide for the automatic operation of the device in the capacity above described.

In the accompanying two sheets of drawings, illustrating one embodiment of my i11- vention, similar figures of reference indicate like parts throughout the several views, in which- Figure 1 is a view in sectional .elevation of my invention applied. Fig. 2 is a sectional plan view thereof. Figs. 3 and 4 are detail sectional views illustrating the construction and operation of the friction driving-gear of the safety appliance; and Fig. 5 is a sectional view in detail of the governor, dac., taken on a line at right angles to the plane of Fig. 1.

Referring to the drawings, 1 represents a portion of an elevatorshaft, and 2 2 are guides arranged upon opposite sides of the shaft and extending throughout the length thereof. I preferably employ guides of T cross-section or the ordinary T-iron, having fixed to or integral therewith a rack-bar 2a, which constitutes the fixed member of the friction-gearing hereinafter referred to.

3 represents a portion of the lower frame of the elevator-car.

44 are twin guide-rollerssupported in bracketed bearings in a manner to project beyond the side beams of the car-frame and of the rack bars or guides.l

5 5 represent vertically-disposed Worms rotatably mounted in bearings 5a 5a upon the car-V frame. These worms, constituting the movable members of the friction-gearing, are arranged in operative relation with the toothed Serial No. 716,769. (No model.)

'guides or rack-bars and are driven at a rate corresponding to the speed of travel of the car, the object being to maintain sufficient clearance between the members so that, though in- 'termeshing, they are normally out of contact and as a result there is no friction.

6 6 represent two friction-pulleys, each of which is mounted upon a shaft 7. These shafts are supported at their inner ends in pivoted bearings 8 8 and near their outer ends in terminal bearings 9 9 of levers 10 10, which latter are pivoted at 11 11 to the carframe. Under the action of springs 12 12, attached to their levers at or near their upper ends, the friction-wheels are normally sustained under constant pressure in contact with the face of the T-guides. During the travel of the elevator-cars these Wheels are caused to rotate, and the motion thus .set up is transmitted to the Worms above referred to through the medium of the intermeshing spur and bevel gearing 13 13 14 14, as shown in Figs. 1 and 2.

15 represents a speed-governor, and. 16 is the vertically-moving shaft thereof, which terminates at its upper end in a conical member of a friction-clutch 17. Supported in the car-frame immediately above the cone and axially alined therewith, the second clutch memberlS is rotatably mounted. This member 18 has formed in part with it a bevel-gear 19, which rotates a threaded sleeve 20 through the intermediate bevel-gear 21, the latter being keyed to or formed integral with the sleeve. A rod 22, threaded into the sleeve, is supported at or near its outer end in a bearing 23 and connected to the upper end of the levers 10 10 by means of cables or chains 24E 24, passing around pulleys 25 25, &c.

26 26 represent brake-shoes which the friction-Wheels engage with more or less pressure when thrown out of contact with the T-guides. These brake-shoes may be fixed or movable and controlled by a lever operated in the elevator-car.

The operation of the device is as follows: Ordinarily in the travel of the elevator-car the speed will not be sufficient to operatethe friction-clutch under the direct control of the governor, and in consequence clearance loei tween the main frietion-gear--t`- e., the worms and racks-will be maintained. When, how- IOO threaded connection the rod 22 is drawn into the sleeve, thereby drawing upon the cables or chains and swinging the levers 10 lO into the position shown bydotted lines in Fig. 4. This movement of the levers carries the friction-Wheels 9 9 out of contact with the guides and into engagement with the brake-shoes, and in consequence the worms cease to be rotated under the action of the driving-gear and are at once forced into engagement with the teeth of the racks or T-guides under more or less pressure-that is to say, if the main cables of the car have parted or become in any manner disarranged and no longer support the car the weight of the latter is then transferred and borne by the Worms, and under its influence or a direct downward pressure the Worms Will continue to revolve, but at a greatly-reduced speed, and the car will descend in safety.

By employing worms of different pitch the speed of travel of the car in its descent, as just described, may be increased or diminished, as will be obvious.

Having thus fully described my invention and the manner in which the same may be applied, what I claim as new isl. A safety device for elevators comprising racks and worms gearing the car in the shaft, driving-gear for the worms consisting'of rotatable and non-rotatable members, the nonrotatable members being fixed in the shaft and the rotatable members carried by the car and a governor controlling the rotatable members of the driving-gear by adjusting them into or out of engagement with the non-rotatable members, as specified.

2. A safetydevice for elevators, comprising racks and worms gearing the carin the shaft, frictional driving-gear for the worms, the non-rotatable members of 'the driving-gear being fixed in the shaft and the rotatable members thereof carried by the ear and a governor controlling the rotatable members by adjusting them into or out of engagement with the non-rotatable members, as specified.

Signed at New York city, in the county of New York and State of New York, this 26th day of April, A. D. 1899.

ALBERT AUGUST ERNEST STER-ZING.

Vitnesses:

LILIAN FOSTER, J. E. PEARsoN. 

